VMS Help EXCHANGE, DIRECTORY, Qualifiers, /BLOCKS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /BLOCKS
       /NOBLOCKS

    Lists the starting block number of the file. This qualifier is
    valid only for directories of RT-11 devices. The first block of
    the device is block number 0. The default is /NOBLOCKS.